1. Field of the Invention
The invention relates to a battery system capable of understanding a deviation in salt concentration in an electrolyte.
2. Description of Related Art
As described in Japanese Patent Application Publication No. 2010-060406 (JP 2010-060406 A), it is known that a deviation in salt concentration in an electrolyte causes an increase in internal resistance value of a secondary battery. In JP 2010-060406 A, it is recognized that, when the difference between an estimated current density estimated from a battery model and a measured current density measured by a current measurement unit (current sensor) becomes larger, the deviation in salt concentration becomes larger, and the internal resistance value of the secondary battery becomes higher. With such recognition, the ratio of the estimated current density and the measured current density is calculated as a battery resistance increase rate.